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Registered:
June 2004
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cam sizzing for boosted 18rgeu
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Sun, 13 November 2005 21:20
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What would you mates suggest for cam size for a boosted 18rgeu motor? I have the stock set, and a 292 duration with .420 lift set that I can use, but I have a place that will weld and regrind them to whatever size I need.
The car will be used as a test mule for different boosting applications; a t04e 50 trim, as well as testing for a vortech v-5 G-trim supercharger, a sc14, and a powerdyne db11a. I have all these in the house now, and will run all of these to see what combination I like the best. I will be posting the results of my findings on here too.
I have been told that a 272 cam is the best for boost in these motors, but what would be a good lift?
All suggestions would be greatly appreciated.
Ryan
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Location:
Canberra
Registered:
July 2005
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 06:29
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the stock cams shouldn't be too much of a hassle in a bossted engine, especially in a 18rgeu. They are relatively mild, but at least you aren't blowing inlet charge straight out the exhaust.
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Location:
Brisbane
Registered:
October 2002
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 06:32
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apparently the stock cams are very good, except for getting some mild work done to the exh side
call surecam in brissie
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 11:11
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i think the only thing that could really be improved upon is lift and lift profile..... but having no real world experience i'm interested to see what your tests will do.
if you are testing the vortex though - DEFINITELY chuck in the 292s 
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 12:19
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more lift = more breathing..
more duration = more rpm possible... and required...
overlap is more of a worry than outright duration..
so what does your 18R rev to?
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Registered:
June 2004
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 19:19
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Oldcorollas,
I am keeping my revs on the 18rgeu to an absolute max of 7k. i gather from your comments that I want a lob profile that holds the valve open at max lift for as long as possible, correct? That would make the lobs very rounded of the top, but also increase the stresses of the valves due to the increases acceleration the will be going through. What are you thinking?
I am thinking that I will actually test all 4 boosted types and both cams. That makes 8 different possibilities/combinations. Then I will probably have 2 different headers/extractors designs as well. So that makes another 6 combinations to add to the other 8...this is going to be a lot of work, but a lot of fun as well!!! I hope to get a lot of really good data out of this project…maybe help a lot of other guys along their journey to find the power they want.
Any other thoughts? I am trying to collect as much information as I can. I do have another set of stock cams that I can have welded and reground to any specs.
Ryan
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 20:11
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| rcodea wrote on Tue, 15 November 2005 06:19 |
Oldcorollas,
I am keeping my revs on the 18rgeu to an absolute max of 7k. i gather from your comments that I want a lob profile that holds the valve open at max lift for as long as possible, correct? That would make the lobs very rounded of the top, but also increase the stresses of the valves due to the increases acceleration the will be going through. What are you thinking?
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thats pretty much what i'm thinking...
smack the valve open, hold it open for as long as possible then close it quick 
overlap will blow charge out the exhaust, and since you are not revving very high, you shouldn't need a long suration cam..
in an NA motor, a 272 should allow you to make power around 7000rpm or more... boosted, it may go to 8000-9000rpm... so basically, any extra rpm you cater for with your cam.. is wasted if you are limiting rpm anyway... if that makes sense...
but lift... lift is always good... you have a nbice reservior of pressurised air just waiting to get in, so you may as well give it the biggest opening
extra stress on valves is not great, but rpm also affects this loading a great deal...
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Registered:
June 2004
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Re: cam sizzing for boosted 18rgeu
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Mon, 14 November 2005 21:09
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So then I have to ask, what would i need for lift? The 292s are .420. Would I need to get something like a stock cam with about .500 lift? Is there really that much room to have that kind of lift?
Ryan
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